In the fuel injection systems set forth in U.S. Pat. No. 5,070,845 issued Dec. 10, 1991 to Avdenko et al., and copending U.S. patent application Ser. No. 08/143595 filed Nov. 1, 1993, fuel systems are disclosed having fuel injectors for metering fuel to a plurality of fuel nozzles. Fuel is distributed through individual fuel lines and is discharged via the nozzles at locations adjacent the engine intake ports. The nozzles disclosed have bodies with a tubular seat member and an opening for the discharge of fuel therethrough. A poppet valve member is operable, relative to the seat member, to interrupt fuel flow through the opening, and an extension spring anchored to the nozzle body and to the valve member urges the valve into a normally closed position against the seat member.
The nozzle bodies are adapted to receive fuel through restriction members that limit the flow of fuel into the bodies, however, the metering function of the members are limited in their fuel metering precision due to a lack of adjustability. It is desirable to precisely control the flow of fuel through the nozzle upon the opening of the valve in order to meet engine performance requirements as well as emissions regulations for internal combustion engines. For a given application, all nozzles in a particular engine should meter equivalent quantities of fuel to the intake upon application of pressurized pulses of fuel to the nozzles. As such, individual nozzle flow must be adjusted to meet a desired static flow, which is typically controlled through valve stroke and fuel flow into the nozzle body.